Catalyst and process for production of acrylic acid

Abstract

There are disclosed: a catalyst which can be used for production of acrylic acid and is excellent in the catalytic performances (e.g. conversion of starting material, selectivity of aimed product) and further has very high physical strength; and a process for production of acrylic acid using this catalyst. The above catalyst for production of acrylic acid is a catalyst which is obtained by a process including the steps of: heating a mixed liquid of starting materials including molybdenum and vanadium as essential components; and then molding the resultant dried material with a liquid binder; and then calcining the resultant molding; with the catalyst being characterized in that the liquid binder is an aqueous liquid of 7.0 to 10.0 in pH. The above process for production of acrylic acid is a process which comprises the step of carrying out catalytic gas phase oxidation of acrolein in the presence of molecular oxygen, thereby producing the acrylic acid; with the process being characterized by using the above catalyst for production of acrylic acid according to the present invention.

1. A process for production of acrylic acid, which comprises the step of carrying out catalytic gas phase oxidation of acrolein in the presence of molecular oxygen, thereby producing the acrylic acid;
 with the step of carrying out catalytic gas phase oxidation using a catalyst which is obtained by a process that includes the steps of: heating a mixed liquid of starting materials including molybdenum and vanadium as essential components; and then molding the resultant dried material with a liquid binder; and then calcining the resultant molding; wherein the liquid binder is an aqueous liquid of 7.0 to 10.0 in pH. 
 
     
     
       2. A process for production of acrylic acid according to  claim 1 , wherein the liquid binder is an aqueous liquid of 7.5 to 9.5 in pH. 
     
     
       3. A process for production of acrylic acid according to  claim 1 , wherein a physical strength of the catalyst is 98.6 mass % or more. 
     
     
       4. A process for production of acrylic acid according to  claim 3 , wherein the physical strength of the catalyst is measured in accordance with the following procedure:
 a) providing a stainless-steel-made reaction tube of 25 mm in inner diameter and 5,000 mm in length and setting said stainless-steel-made reaction tube in a vertical direction; 
 b) closing a lower end of said stainless-steel-made reaction tube with a stainless-steel-made receiving plate of 1 mm in thickness; 
 c) dropping 50 g of the catalyst from an upper end of the stainless-steel-made reaction tube into the stainless-steel-made reaction tube; 
 d) removing the stainless-steel-made receiving plate, having the catalyst that has been dropped, from the stainless-steel-made reaction tube such that the catalyst is extracted from the stainless-steel-made reaction tube; 
 e) sieving the catalyst that has been extracted with a sieve having a mesh opening size of 4 mm; and 
 f) wherein the physical strength (mass %) of the catalyst equals [(mass of catalyst remaining on sieve)/(mass of catalyst as dropped from the upper end of the stainless-steel-made reaction tube)]×100.